Forced draft burner for portable boiler flame chambers



Aug- 29 1944 n J. W. ADAMS 2,356,729

FOR PORTABLE BOILER FLAMEl CHAMBES FORCED DRAFT BURNER iiled Nov. 4, 1941 Patented Aug. 29, 1944 UNITED STATES TENT OFFICE FORCED DRAFT BURNER FOR PORTABLE BOILER. FLAME CHAMBERS James W. Adams. Dallas, Tex.. assigner to Oil Well Supply Company, a corporation of New Jersey 3 Claims.

This invention relates to improvements in forced draft burners for portable boiler flame chambers, such chambers being known in the oil drilling art as ducks nests and being utilized for setting up and ring portable locomotive type boilers in the oil fields.

In oil field operations, oil and gas are available boiler fuels and have been utilized with varying degrees of eficiency. While portable locomotive type boilers are standard equipment, the firing of such boilers With the available uid fuels has generally been characterized by the low eiciencies obtained. Such results are apparently due to the failure to obtain sufficient combustion and due to the variable structural conditions resulting from the arbitrary erection burners employed for the said fuels. H

My invention has in view to provide an efcient forced draft burner in combination with a name chamber or ducks nest to obtain a highly ecient and uniform combustion of liquid or gaseous fuels or a combination of both of said fuels in boilers of the character stated.

The invention also contemplates improvements in the burner structure for producing and burning a combustible admixture of liquid or gaseous fuels or both, while providing adequate forced draft for the boiler.

Additional objects and advantages will become apparent from the following description taken in connection with the accompanying drawing, wherein:

Fig. 1 is a side elevational view of a portion of a locomotive type boiler showing the application of my invention thereto;

Fig. 2 is a cross sectional View taken on the line II-II of Fig. l;

Fig. 3 is an enlarged sectional View taken on the line III-III of Fig. 2, particularly showing the forced draft burner and the fuel combustion;

Fig. 4 is an enlarged fragmentary sectional view of the gas ring of the burner;

Fig. 5 is a face View of the burner construction; and

Fig. 6 is an enlarged detail view of a portion of the burner.

Referring to the drawing, 2 designates a portable steam boiler of the locomotive type, including a rebox 3, and a re tube section 4, the rebox section having the usual depending water legs 5.

Supporting said boiler by the water legs 5 thereof, I provide a portable flame chamber or ducks nest 6, including a pair of skids 'I and an end member 8 extending between the skids at the rear end of the boiler and flame chamber. Angle members 9 connect the other ends of the skids l beneath the juncture of the iirebox 3 and re tube section 4 at the front end of the name chamber, and a rectangular refractory lining I0 is mounted Within the metal frame formed by saidskids 'I and members 8 and 9, said lining extending upwardly into the rebox 3.

Suitable fastening means,such as stay bolts I I, removably secure the ducks nest to the water legs 5, the latter resting upon the upper surfaces of the skids l, end member 8, and the upper angle member 9, and being provided with an intervening sealing gasket I2, such as asbestos rope or the like, to form an air-tight connection between the interior of the ame chamber 6 and the lirebox 3. Thus, the flame chamber becomes a continuation of the rebox, both for purposes of mounting-and support of the boiler, and for combustion of fuel.

My invention includes a burner in conjunction with said ame chamber 6, said burner being mountedat the front end of the chamber as by means of a transverse support I3, and having means for supplying a forced draft, providing air for admiXture with the fuel and forcing the burning mixture through the flame chamber and boiler in such a manner as to effect substantially complete combustion. In addition, the burner includes associated means for supplying liquid or gaseous fuel or both for combustion as here- I inafter described.

Thus, Ill indicates a blower or fan driven by suitable means, such as a steam turbine I5, said fan being rotatable in a horizontal tubular shroud I6 mounted in the support I3. Suitable brackets or supports I'I are provided for supporting the turbine I5 on the flame chamber structure. I

The front refractory Wall I8 of the flame chamber 6 is horizontally apertured to form a burner opening I 9 in alignment with the fan I4. Shroud I6 is connected to opening I9 by a frusto-conical reducing connection 20, thereby forming a Venturi throat for the blower or fan which terminates in a discharge orifice a at said burner opening i9. Fan or blower I4 thereby delivers a horizontal air blast from front to rear of the flame chamber, the throat 2D serving to increase the entering velocity of the air while at the same time densifying or enhancing the volume of the air discharged from orifice a about the periphery of the opening I9 as illustrated by the distribution of the horizontal arrows indicating such flow in Fig. 3.

For the purpose of employing liquid fuel, such as oil, the fan I4 is provided with a centrifugal slinging or atomizing cup 2| centrally secured to and rotatable with the fan hub, said cup being hollow and having an open free end 22. Fuel or oil is supplied thereto by means of a conduit 23 having a nozzle 24 extending inwardly through the open end 22 of said cup. Hence, upon supplying on to the cup While the same is rotated at high speed by the fan I4, the perimeter or lip 25 of the cup will sling the oil in a finely divided spray outwardly beyond the orifice a into the air stream from the fan within the opening I9, as indicated at 26 in Figs. 3 and 6, forming a highly combustible mixture which will burn in the flame chamber upon ignition,

A steam ring 2Ia may be provided for injecting steam into the oil spray 26 as shown at 25a in Figs. 3 and 6, as when using a heavy oil, thereby assisting in atomizing the oil upon its adrnixture with the air.

The abrupt or right angle termination of the horizontal wall of opening I9 with the inner vertical face of the chamber wall I8 assists in producing admixture of the fuel particles and air due to the turbulence produced thereby, thus insuring highly efficient combustion without loss of fuel.

My invention also contemplates the conjoint or separate use of a gaseous fuel, as for example, casing head gas, and for this purpose I provide a manifold 2l in the formof an annular chamber surrounding the throat member 20, said manifold being formed with an annular series of jets or apertures 28 disposed substantially in the plane of the orifice a. Said apertures 28 are preferably disposed at an angle of about 45de grees to the fan axis, whereby the jets of gas are discharged into the air stream from the fan I4 in a radially inward and forward direction beyond the orice a, said gas jets being indicated at 29 in Figs. 3 and 4. Hence, upon supplying gas under pressure to said manifold 2'I as by a supply pipe 30, the gas will have efcient admixture with the peripheral portion of the air stream from the fan I4 for combustion upon ignition. Also, when desired, gas and oil both may be mixed with the air blast for their combined combustion.

The resulting combustion will progress horizontally across the flame chamber 6 from front to rear under the pressure and velocity of the air stream from the fan I4, the flame being turned and reversed by the rear wall of the name chamber and thence returning forwardly and upwardly to the lire tube section 4 of the boiler, as indicated by the arrows in Fig. 1. The prolongation of the combustion in this manner under the forced draft of the fan or blower produces highly eicient heating, whereby the boiler is efliciently fired with improved performance and economy. In actual test, the evaporation of an oil field boiler was doubled in comparison with the results obtained under former ring practice, and reached its maximum capacity when fired by means of the present invention, employing both oil and gas as fuel.

It will be noted that, by reason of the forced air blast of the present invention, the boiler may be set up and operated in an eflicient and uniform manner without the usual high stack, which stacks are a constant source of trouble and expense in portable equipment of the kind used in the oil fields. Further, the provision of the com bined burner and flame chamber fixes and makes constant the combustion characteristics, such as the draft, admixture and combustion volume, whereby the boiler may be taken down and set up in different locations with insured uniformity and efliciency of operation.

Various changes and modifications are contemplated within the scope of the following claims.

I claim:

l. The combination with a portable flame chamber'adapted to be disposed beneath the firebox of a locomotive type boiler as a continuation of said firebox, of a burner mounted at the front of said chamber and directed horizontally rearward thereof, said burner including a forced draft fan, a horizontal shroud about the fan, said flame chamber having a horizontal opening receiving the blast from the fan, a frusto-conical reducer connected with the shroud and terminating in an orice at the opening in said iiame chamber, said chamber opening terminating abruptly inwardly of the flame chamber, and means for injecting fuel into the air stream from the fan within said horizontal opening beyond the plane of said orice, thereby forming a combustible mixture which upon ignition will burn in a horizontal path from front to rear of the ame chamber and thence in the firebox under the forced draft from the fan.

2. In a device of the character described, a forced draft fan, a horizontal shroud about the fan, a frusto-conical reducer connected with the shroud and terminating in a discharge orifice, a .liquid fuel slinging cup secured to and rotatable with the fan, the perimeter of the open end of said cup comprising a slinging lip to centrifugally sling a liquid fuel from the cup outwardly into the air str-earn from the fan in a plane beyond thatl of said orifice, means for supplying a liquid fuel to the interior o-f the cup, an annular fuel gas manifold surrounding the reducer, said manifold having a series of apertures supplying gas inwardly and forwardly into the air stream from the fan, the said apertures being disposed substantially in the plane of the orifice, and means supplying fuel gas to said manifold.

3. In a device of the character described, a forced draft fan, a horizontal shroud abo-ut the fan, a frusto-conical reducer connected with the shroud and terminating in a discharge orifice, a liquid fuel slinging cup secured to and rotatable with the fan, the perimeter of the open end of said cup comprising a slinging lip to centrifugally sling a liquid fuel from the cup outwardly into the air stream from the fan in a plane beyond that of said orifice, means for supplying a liquid fuel to the interior of the cup, an annular fuel gas manifold surrounding the reducer, said manifold having a series of apertures supplying gas inwardly and forwardly into the air stream from the fan, the said apertures being disposed substantially in the plane of the orifice, means supplying fuel gas to said manifold, and a steam ring surrounding said cup for discharging steam into the liquid fuel from the cup.

JAMES W. ADAMS. 

